Research Project: Mikro ve Nano Tabanlı Sektör Tasarım ve Üretimi İçin Doktoralı Araştırma Yetiştirilmesi
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Contributors
Funders
ID
TB.00430
Authors
Alaca, Burhanettin Erdem
Faculty Member
Publications
Stencil-based selective surface functionalization of silicon nanowires in 3D device architectures for next-generation biochemical sensors
(American Chemical Society, 2024) Akıncı, Seçkin; Alaca, Burhanettin Erdem; Ali, Basit; Özkan, Sena Nur; Öztürk, Ece; Karimzadehkhouei, Mehrdad; Esfahani, Mohammad Nasr; Leblebici, Yusuf; Department of Mechanical Engineering; Graduate School of Health Sciences; Graduate School of Sciences and Engineering; KUTTAM (Koç University Research Center for Translational Medicine); KUYTAM (Koç University Surface Science and Technology Center); n2STAR (Koç University Nanofabrication and Nanocharacterization Center for Scientifc and Technological Advanced Research); School of Medicine; Yes; College of Engineering; GRADUATE SCHOOL OF HEALTH SCIENCES; GRADUATE SCHOOL OF SCIENCES AND ENGINEERING; Research Center; SCHOOL OF MEDICINE
Surface functionalization of 1D materials such as silicon nanowires is a critical preparation technology for biochemical sensing. However, existing nonselective functionalization techniques result in nonlocal binding and contamination, with potential device damage risks. Associated risks are further exacerbated for next-generation devices of a 3D nature with challenging topographies. Such 3D devices draw inspiration from the out-of-plane evolution of planar transistors to FinFETs and to today's gate-all-around transistors. This study is the first reported technological work addressing stencil-based surface decoration and selective functionalization of a suspended silicon nanowire building block embedded within such a device that involves two-order-of-magnitude thicker features compared to the nanowire critical dimensions. A gold pattern resolution of 3.0 mu m atop the silicon nanowires is achieved with a stencil aperture critical dimension of 2.2 mu m, accompanied by a die-level registration accuracy of 1.2 +/- 0.3 mu m. Plasma-enhanced chemical vapor deposition-based silicon nitride stencil membranes as large as 300 x 300 mu m2 are used to define the apertures without any membrane fracture during fabrication and membrane cleaning. The pattern-blurring aspect as a resolution-limiting factor is assessed by using 24 individual nanowire devices. Finally, gold-patterned silicon nanowires are functionalized using thiolated heparin and employed for selective attachment and detection of the human recombinant basic fibroblast growth factor (FGF-2). With the potential involvement in angiogenesis, the process of new blood vessel formation crucial for tumor growth, FGF-2 can serve as a potential prognostic biomarker in oncology. Demonstrated selectively on nanowires with high pattern resolution, the proposed functionalization approach offers possibilities for parallel sensing using vast nanowire arrays embedded in 3D device architectures developed for next-generation biochemical sensors in addition to serving various encapsulation and packaging needs.
Silicon nanowires driving miniaturization of microelectromechanical systems physical sensors: a review
(Wiley-V C H Verlag Gmbh, 2023) Ali, Basit; Alaca, Burhanettin Erdem; Karimzadehkhouei, Mehrdad; Jedari Ghourichaei, Masoud; KUYTAM (Koç University Surface Science and Technology Center); Department of Mechanical Engineering; n2STAR (Koç University Nanofabrication and Nanocharacterization Center for Scientifc and Technological Advanced Research); Graduate School of Sciences and Engineering; Yes; College of Engineering; GRADUATE SCHOOL OF SCIENCES AND ENGINEERING; Research Center
The miniaturization of microelectromechanical systems (MEMS) physical sensors is driven by global connectivity needs and is closely linked to emerging digital technologies and the Internet of Things. Strong technical advantages of miniaturization such as improved sensitivity, functionality, and power consumption are accompanied by significant economic benefits due to semiconductor manufacturing. Hence, the trend to produce smaller sensors and their driving force resemble very much those of the miniaturization of integrated circuits (ICs) as described by Moore's law. In this respect, with its IC-, and MEMS-compatibility, and scalability, the silicon nanowire is frequently employed in frontier research as the sensor building block replacing conventional sensors. The integration of the silicon nanowire with MEMS has thus generated a multiscale hybrid architecture, where the silicon nanowire serves as the piezoresistive transducer and MEMS provide an interface with external forces, such as inertial or magnetic. This approach has been reported for almost all physical sensor types over the last decade. These sensors are reviewed here with detailed classification. In each case, associated technological challenges and comparisons with conventional counterparts are provided. Future directions and opportunities are highlighted.
Powering smart contact lenses for continuous health monitoring: Recent advancements and future challenges
(Elsevier, 2022) Beker, Levent; İstif, Emin; Mirlou, Fariborz; Mirzajani, Hadi; Singh, Rahul; N/A; Department of Mechanical Engineering; Department of Electrical and Electronics Engineering; KUTTAM (Koç University Research Center for Translational Medicine); Yes; College of Engineering; Research Center
As the tear is noninvasively and continuously available, it has been turned into a convenient biological interface as a wearable medical device for out-of-hospital and self-monitoring applications. Recent progress in integrated circuits (ICs) and biosensors coupled with wireless data communication techniques have led to the implementation of smart contact lenses that can continuously sample tear fluid, analyze physiological conditions, and wirelessly transmit data to an electronic device such as smartphone, which can send data to relevant healthcare units. Continuous analyte monitoring is one of the significant characteristics of wearable biosensors. However, despite several advantages over other on-skin wearable medical devices, batteries cannot be incorporated on smart contact lenses for continuous electrical power supply due to the limited area. Herein, we review the progress of power delivery techniques of smart contact lenses for the first time. Different approaches, including wireless power transmission (WPT), biofuel cells, supercapacitors, flexible batteries, wired connections, and hybrid methods, are thoroughly discussed to understand the principles of self-sustainable contact lens biosensors comprehensively. Additionally, recent progress in contact lens biosensors is reviewed in detail, thereby providing the prospects for further developments of smart contact lenses as a common biosensing platform for various disease monitoring and diagnostic applications.
An ultra-compact and wireless tag for battery-free sweat glucose monitoring
(Elsevier, 2022) Abbasiasl, Taher; Bathaei, Mohammad Javad; Beker, Levent; Dağ, Çağdaş; Dereli, Dilek Yazıcı; Deyneli, Oğuzhan; İstif, Emin; Mirlou, Fariborz; Mirzajani, Hadi; N/A; Department of Mechanical Engineering; Graduate School of Sciences and Engineering; KUISCID (Koç University İşbank Center for Infectious Diseases); KUTTAM (Koç University Research Center for Translational Medicine); n2STAR (Koç University Nanofabrication and Nanocharacterization Center for Scientifc and Technological Advanced Research); School of Medicine; Department of Molecular Biology and Genetics; Yes; College of Engineering; GRADUATE SCHOOL OF SCIENCES AND ENGINEERING; Research Center; SCHOOL OF MEDICINE; College of Sciences
Glucose monitoring before, during, and after exercise is essential for people with diabetes as exercise increases the risk of activity-induced hyper- and hypo-glycemic events. The situation is even more challenging for athletes with diabetes as they have impaired metabolic control compared to sedentary individuals. In this regard, a compact and noninvasive wearable glucose monitoring device that can be easily worn is critical to enabling glucose monitoring. This report presents an ultra-compact glucose tag with a footprint and weight of 1.2 cm(2) and 0.13 g, respectively, for sweat analysis. The device comprises a near field communication (NFC) chip, antenna, electrochemical sensor, and microfluidic channels implemented in different material layers. The device has a flexible and conformal structure and can be easily attached to different body parts. The battery-less operation of the device was enabled by NFC-based wireless power transmission and the compact antenna. Femtosecond laser ablation was employed to fabricate a highly compact and flexible NFC antenna. The proposed device demonstrated excellent operating characteristics with a limit of detection (LOD), limit of quantification (LOQ), and sensitivity of 24 mu M, 74 mu M, and 1.27 mu A cm(-2) mM(-1), respectively. The response of the proposed sensor in sweat glucose detection and quantification was validated by nuclear magnetic resonance spectroscopy (NMR). Also, the device's capability in attachment to the body, sweat collection, and glucose measurement was demonstrated through in vitro and in vivo experiments, and satisfactory results were obtained.
Characterization of a hybrid nanowire-MEMS force sensor using direct actuation
(IOP Publishing Ltd, 2025) Jedari Ghourichaei, Masoud; Karimzadehkhouei, Mehrdad; Aydın, Onur; Aksoy, Bekir; Nadar, Gökhan; Alaca, Burhanettin Erdem; Nadar, Gökhan; Jedari Ghourichaei, Masoud; Pruchnik, Bartosz; Kwoka, Krzysztof; Piasecki, Tomasz; Aydogan, Cemal; Rangelow, Ivo W.; Yalcinkaya, Arda Deniz; Bayraktar, Halil; Gotszalk, Teodor; Department of Mechanical Engineering; n2STAR (Koç University Nanofabrication and Nanocharacterization Center for Scientifc and Technological Advanced Research); KUYTAM (Koç University Surface Science and Technology Center); Yes; Aydın, Onur; Aksoy, Bekir; College of Engineering; Research Center
In this study, we describe a process of characterization of a 3-axial force sensor with piezoresistive silicon nanowires. We present a unique method for determining the gauge factor (GF) of a volumetric structure with a stiffness exceeding 10(5)N m(-1) and resonant frequencies above 10 MHz. We employed an uncommon Lab-in-Scanning Electron Microscope (Lab-in-SEM, LIS) approach to perform a full characterization schedule under vacuum conditions using direct actuation with nanomanipulators. We discuss the force evaluation errors arising from the sample support stiffness. Finally, we present the results of GF measurements of the multi-axially investigated device with GF of over 20 for axial and over 40 for transverse loading.
